Instrument for inserting an interspinous process implant

Abstract

An insertion device for deploying an implant includes an elongated main body having a distal locking portion for coupling to the implant and a proximal handle portion. The main body defines a central passage and the distal locking portion has outer ridges and slots to allow the outer ridges to flex radially inward when mounting to the implant. A plunger slides in the central passage for movement between an unlocked position for mounting the implant on the distal locking portion, a locked position for locking the implant on the distal locking portion, and an insertion instrument deployed position for deploying the actuation plunger to move the blades from the stowed position to the deployed position. A spike cap drive rotatably mounts on the main body having a socket end for engaging a drive nut on the implant to, in turn, move the spike cap.

What is claimed is: 
     
       1. An insertion device for a spinal implant, wherein the spinal implant includes:
 a) an elongated body to function as a spacer placed in a target interspinous process space between two adjacent spinous processes, wherein the body defines an interior and a proximal internal recess for access to the interior, the proximal internal recess forming a transverse groove; 
 b) a distal anchor that is at least partially threaded and has opposing radially deployable blades mounted for rotation about a pin transversely mounted in the interior; 
 c) a proximal anchor including a spike cap mounted to slide along the body and a drive nut mounted for longitudinal movement along the body between a first position spaced apart from the distal anchor and a second position relatively closer to the distal anchor to thereby compress the two adjacent spinous processes between the spike cap and the distal anchor; and 
 d) an actuation plunger slidably inside the interior for moving the blades from a stowed position to an implant deployed position, the insertion device comprising:
 i) an elongated main body having a distal locking portion for coupling to the implant and a proximal handle portion, the main body defining a central passage and the distal locking portion having outer ridges and at least one slot to allow at least one of the outer ridges to flex radially inward; 
 ii) a plunger slideably coupled in the central passage for movement between an unlocked position for mounting the implant on the distal locking portion, a locked position for locking the implant on the distal locking portion, and an insertion instrument deployed position for deploying the actuation plunger to move the blades from the stowed position to the deployed position; 
 iii) a spike cap drive rotatably mounted on the main body having a socket end for engaging the drive nut to, in turn, move the spike cap; and 
 iv) a plunger stop coupled to the main body and having a central passage substantially aligned with the central passage of the main body and a boss protruding into the central passage, wherein the plunger forms a three-part groove that captures the boss as the plunger slides and rotates within the central passage, the three-part groove having a first axial part that defines the unlocked position, an intermediate radial part that defines the locked position, and a second axial part that defines the insertion instrument deployed position. 
 
 
     
     
       2. An insertion instrument as recited in  claim 1 , wherein:
 a) in the unlocked position of the plunger, when the implant is mounted on the insertion instrument, the outer ridges are engaged in the transverse groove; 
 b) in the locked position of the plunger, the outer ridges are engaged in the transverse groove and the plunger extends through the central passage to be concentric with the outer ridges; and 
 c) in the insertion instrument deployed position of the plunger, the plunger extends out of the central passage to move the actuation plunger of the implant. 
 
     
     
       3. An insertion instrument as recited in  claim 1 , further comprising an adapter matched to the implant for coupling the socket end to the drive nut of the implant. 
     
     
       4. An insertion instrument as recited in  claim 1 , wherein the spike cap is keyed to the implant body to prevent rotation when driven and the implant has flat portions that allow efficient compression of the implant when engaged in the spinous processes. 
     
     
       5. An insertion instrument as recited in  claim 1 , further comprising polytetrafluoroethylene (PTFE) on at least one of the spike cap drive or main body to reduce wear and provide smooth operation as the spike cap drive is rotated. 
     
     
       6. An insertion instrument for inserting an implant having a body that defines a mounting recess and includes a selectively deployable proximal anchor, the insertion instrument comprising:
 an elongated main body having a proximal handle portion and a slotted distal portion that selectively couples to the mounting recess of the implant; 
 a plunger slidably engaged in a central passage of the elongated main body for fixing the implant to the elongated main body by selectively filling the central passage within the slotted distal portion; and 
 a spike cap drive concentrically located about the plunger and elongated main body to deploy the proximal anchor of the implant, wherein the spike cap drive defines an axial passage and includes a proximal handle portion slidably coupled with a smaller radius interlocking portion that terminates in a socket end, and wherein the smaller radius interlocking portion can be locked in a retracted position and the spike cap drive has a spring that is mounted within the proximal handle portion for biasing the smaller radius interlocking portion distally. 
 
     
     
       7. An insertion instrument as recited in  claim 6 , wherein the implant defines an interior connected to the mounting recess, the implant further includes selectively deployable distal blades, and the plunger deploys the distal blades by extending out of the central passage into the interior. 
     
     
       8. An insertion instrument as recited in  claim 6 , wherein the mounting recess has a transverse groove, the distal portion has ridges that snap into the transverse groove. 
     
     
       9. An insertion instrument as recited in  claim 6 , wherein the plunger moves between an unlocked position for mounting the implant on the distal portion, a locked position for locking the implant on the distal locking portion, and an insertion instrument deployed position for deploying the blade.